You can't. Because "creativity" is not protected by law, everyone can imagine that anyone can use your creativity for free (after they know or understand your creativity), and once the creativity really becomes a product, it is difficult for you to apply for a patent (because of the loss of novelty), and the patent is protected by law. Once your idea is patented, others must get your consent before you can sell you.
So, if you want to sell your idea, you must first turn it into a patent!